Abstract
To the Editor:
A previously well 35-year-old professional photographer from New York City with near-sighted vision had his prescription sunglasses accidentally crushed on the first day photographing a 7-day 150-mile ultra-endurance race through the Gobi Desert near Kashgar, China (altitude 1289 m, latitude 39° N). The conditions were sunny and warm, and while the man usually wears sunglasses while shooting in extreme conditions “from morning to dusk,” he spent the first day without sunglasses (wearing nontinted prescription glasses with mild ultraviolet [UV] protection). In the evening of the first day, a mild discomfort was felt in the right eye, which had spontaneously resolved upon awakening.
The morning of the second day the photographer continued to wear prescription glasses and quickly experienced mild photophobia in the right eye. After 2 to 3 hours there was a sharp pain in the right eye and he found it difficult to keep it open due to increasing severity photophobia and pain; the left eye continued to be asymptomatic. Around noon the victim experienced pain relief by sitting in a darkened truck. The symptoms ranged from a “sandpaper roughness” to an “exquisite, penetrating, stabbing” pain. By late afternoon, the right eye had injected conjunctiva, with eyelid and eyebrow swelling. The patient also complained of a dull, retro-orbital discomfort that he found similar to a migraine or sinus infection, and sought medical care.
The expedition physician who treated the patient in the evening observed right periorbital and eyelid edema, with intact extraocular movements and good pupillary response to accommodation and light, with marked photophobia. The patient had a horizontal band of injected conjunctiva through the width of the eye, narrower than the diameter of the iris. There was sparing of conjunctival injection superior and inferior to the affected area. No corneal clouding was noted. The patient was treated with oral acetaminophen and codeine, ophthalmic anesthetic drops, and the eye was patched. No fluroscein staining or slit lamp examination was available, and no topical antibiotics were applied.
The patient wore nonprescription sunglasses on day 3, and continued taking acetaminophen for the remaining week with symptomatic relief. However the mild irritation in the right eye continued, as well as severe photophobia in daylight and irritation from indoor lights and computer screens. On recheck examinations over the next few days no signs of worsening conjunctival injection or corneal changes were noted.
Upon returning home, the patient experienced residual photophobia to both outdoor and indoor light, as well as irritation by television and computers. Also, the infraorbital area was susceptible to painful swelling as well as persisting retro-orbital pain. These symptoms were found to be relieved by dark areas, and spontaneously resolved by 3 weeks after the expedition. No follow-up ophthalmologic evaluation was done.
UV keratitis and conjunctivitis are a relatively common injury among outdoor enthusiasts, where eyes are exposed to high levels of UVB radiation that can lead to inflammation of the cornea (keratitis) and conjunctival linings of the eyelids and eye socket. Injury typically results from improper ultraviolet eye protection and is caused by direct epithelial damage, 1 and injury may be compounded by dry air and wind. 2 Patients usually notice intense pain to the eyes 6 to 12 hours after exposure. Typically, UV keratitis presents with bilateral, severe eye pain, photophobia, injection, and an inability to open the eyes. 1 UV conjunctivitis often leads to inflammation, conjunctival injection, and periorbital edema. It is believed that the pain associated with UV keratitis results from epithelial damage or loss, but sparing of the irritated subepithelial axons. 3 Although pain is often severe, the duration of disease is generally self-limited. 4 Animal studies looking at induced photokeratitis report re-epithelialization within 24 to 72 hours. 5 In 1 ophthalmologic case report, persistent conjunctival irritation and residual visual derangement from photokeratitis took 1 month to completely resolve. 6
Unilateral keratoconjunctivitis is usually caused by a foreign body, infection, or contact lens irritation. In the outdoors, environmental factors such as ultraviolet injury must be entertained. The patient's profession was possibly a contributing factor to the unique unilateral involvement—as he kept his asymptomatic left eye closed (and protected) while taking photographs, and the affected right eye open, looking through a viewfinder while not wearing protective eyewear, predisposing him to UV radiation injury. The observed horizontal band of injected conjunctiva corresponded to the areas exposed between the open eyelids; the bordering superior and inferior unaffected conjunctiva was protected by the partially closed lids. Also, periorbital and eyelid edema are not uncommon findings in severe UV conjunctivitis. It is also possible that this patient was at increased risk for keratoconjunctivitis due to eye dryness from constantly looking through the camera viewfinder. It is unknown if the properties of the single-lens reflex camera (optical prism, lenses) contributed to the injury. To our knowledge, no studies have been conducted looking at single-lens reflex cameras and corneal or conjunctival injury from changes in light intensity through the viewfinder.
Differential diagnoses for prolonged orbital pain and photosensitivity include more severe diseases such as infection, corneal erosion, ulcer, or exposure keratopathy. The short duration of exposure prior to symptom onset and lack of intrinsic eye defects that predispose to exposure keratopathy make this diagnosis unlikely. Repeat examinations found improved inflammation (without antibiotics), making an infection doubtful. While no corneal clouding was observed by the treating physician, the absence of ophthalmologic follow-up to diagnose corneal erosion or availability of fluoroscein staining to note the classic pinpoint epithelial defects of UV keratitis makes a definitive diagnoses challenging.
This report reiterates the importance of proper ultraviolet eye protection in the outdoors, as well as unique injury contributing factors found in professional media support staff in expedition environments. This case also suggests the potential for further study on single-lens reflex cameras and their possible risk in exacerbating photokeratitis. A unilateral presentation should not eliminate UV keratoconjunctivits from the differential diagnosis of a unilateral acutely painful and red eye in an outdoor environment.